The invention resides in a frictional engagement mechanism, that is a braking or locking arrangement for use in connection with a carriage guided by at least one guide rail wherein the arrangement comprises at least one frictional engagement structure which is operable by means of a sliding wedge drive. The wedge drive includes at least a pressure member, which is supported in a housing and which can be pressed against the guide rail. For engaging the frictional braking or clamping arrangement, the slide wedge drive is moved by a spring force and/or a pneumatic or hydraulic pressure force in one direction and for releasing, it is moved by a pneumatic or hydraulic pressure force of at least one piston in the opposite direction. The piston or pistons are arranged in at least one multistage through bore whose center line is oriented parallel to the longitudinal guide rail direction. The slide wedge of the slide wedge drive acts via at least one roller body on a pressure member and the roller body or bodies are supported in a cage which is displaceable in the longitudinal guide rail direction of the piston or pistons.
DE 102 07 605 C1 and DE 2000 2915U1 disclose such a brake- and/or clamping arrangement. Herein the cage, in which, among others, the roll members of the slide wedge drive are supported, is disposed in alignment with at least one for example, pneumatically operated cylinder-piston unit.
US 2005/0183907 A1 discloses a brake and/or clamping arrangement wherein the force of two drives of the arrangement is redirected by two opposite wedge drives to provide a clamping force effective on a guide rail. Each wedge drive includes a slide wedge, which carries at each support flank two ball bearings. The single slide wedge is guided in a slot of the respective pressure member.
It is the object of the present invention to provide a braking and/or clamping arrangement with a high clamping force and high form stability but which requires relatively little space and little servicing while it is easy and safe to handle and which operates fast and almost without any wear.